Electrical contacts



p s. u. HOPPER arm. 2,449,479

ELECTRICAL CONTACTS Filfld NOV- 19, 1945 IN VENT'OZS. W 5 40/4312 llappcr and Patented Sept. 14,1948

ELECTRICAL CONTACTS Stanley David Hopper and Ernst Heinrich Hermann Hassler, Staflord, England, asslgnors to The English Electric Company Limited, Lon- I don, England, a British company Application lilovember 19, 1945, Serial No. 629,659 In Great Britain November 28, 1944 This invention relates to an electrlc contact device for connecting together two conducting members, one of which is axially movable relative to the other. Such a contact may be used, for exampleior connecting the sections of a telescopic busbar or for mak ng the connection to the movable contact of a gas-blast circuit breaker or for the rubbing contacts of an in-line" isolator.

tween which the tubular isolating link.3 is to be connected, are carried in a busbar chamber 4 which has a section removed to allow for the insertion of an isolating chamber 5. A tubular contact 6 is secured to the busbar l by means of bolts 7 whilst a further tubular contact 8 having a groove 9 therein, is secured to the busbar 2 by means of bolts l 0.

The isolating link 3 is supported me. bearing ring ll forming a part of the isolating chamber 4 and has secured at the left hand end thereof one form of contact device according to the invention. The contact device comprisesa helical- Claims. (01. 200-163) of contact device according to the invention, This contact device is again formed of a helically coiled conductor l8 located in the groove 9 in the tubular contact 8. The clearance space between the bore ll and the bottom'of the groove 9 is again less than the normal diameter of the individual turns of the conductor l8 so that when the isolator is closed the turns will be distorted to such a position that they lie obliquely across the gap to provide the necessary contact pressure. Furthermore, in order to facilitate reclosure of the link after an opening operation, the width of the groove 9 is made slightly less than the diameter of the individual turns of the conductor l8. This results in the turns always being tilted sideways relative to the axis of the contact 8 even when the conductor is disengaged therefrom rowness of the grooves, the turns will, of course,

ly coiled conductor l2 embracing the tubularcontact 6 and loosely held between cheek plates l3 separated from each other by a contact plate ll, the cheek plates l3 and the contact plate It being secured to the isolating link 3 by means of bolts 15. a g

The individual turns of the conductor I! are made of greater diameter than the radial clearance space betweenthe contact 6 and the bore IB of the contact plate l4 sothat the conductor can only be inserted in place by distorting the helix in such a way that the individual turns lie obliquely across the clearance space. The helix resists this distortion and so the inner parts of each'turn bear with considerable force against the contact 6 over which they rub while the outer parts bear with equal, and opposite force against the bore l6 of the contact plate H. A considerable contact pressure'ls thereby obtained and the individual turns of the conductor l2 provide a large number of independent contacts.

The other end of the isolating link 3 has an internal borel! which bears against another form quired to be connected together.

in the isolator closed position be tilted both sideways and obliquely. f

The isolating link 3 is operated by a handle 19 pivoted at 20 and having an insulated fork 2i I thereon engaging pins 22 on the link 3. A flange 23 on the link 3 limits axlal'niovement in the closing direction whilst. a stop plate 24 secured to the link by bolts 25 limits the axial movement in the opening direction.

It will be understood, of course, that the contact device is not limited in its application to an "in-line? isolator butmay be applied to any device in which two contact members, one of which is axially movable relative to the other, are re- Furthermore, the contact members may not necessarilybe of circular form but may be oval or of some other shape such assquare or rectangular, preferably with rounded corners. The turns of the helix may also be oval or of other elongated shape.

What we claim as our invention and desire to secure by Letters Patent is:

1. A disconnect switch comprising an inner contact member, an outer enveloping contact member, said contact members being axially movable relative to each other and having a radial faces of said contact members, axially opposed faces on one of said contactmembers between which said conductor is disposed, and said individual turns being of greater diameter than the distance between said axially opposed faces and tilted sideways thereacross by contact with said axially opposed faces.

2. In a disconnect switch comprising an inner contact member and an outer enveloping contact member, said contact members being movable relative to each other and radially spaced from each other, axially opposed faces on one of said contact members, a helically coiled conductor disposed in the space between said contact members, the individual turns of said conductor being of greater diameter than the distance between said axially opposed faces and tilted sideways thereacross by contact with said axially opposed faces.

3. In a disconnect switch comprising an inner contact member and an outer enveloping contact member, said contact members being movable relative to each other and radially spaced from each other, axially opposed faces on one of said contact members, the radial space between said contact members and the axial space between said axially opposed faces forming an annular space of rectangular cross section, a hellcally coiled conductor disposed in said annular space. the individual turns of said conductor being of greater diameter than the radial and axial dimensions of said annular space and tilted substantially diagonally of the cross section of said annular space by confinement therein.

4. In a disconnect switch comprising an inner contact member, an outer enveloping contact member, said contact members being movable relative to each other and radially spaced from each other, axially opposed faces on one of said contact members, the radial space between said contact members and the axial space between said axially opposed faces forming an annular space of rectangular cross section, a helically coiled conductor disposed in said annular space, the individual turns of said conductor being of greater diameter than the radial space between said contact members and also greater than the space between said axially opposed faces, and said individual turns being tilted both radially and axially of said contact members by contact with the radially opposed surfaces of said contact members and by contact with said axially opposed faces.

5. In a disconnect switch comprising an inner contact member and an outer contact member, said contact members being movable axially relative to each other to separate said contact members and being spaced radially from each other, axially opposed faces on one of said contact mem. bers, the contact members and said axially opposed facesdeflning an annular space of rectangular cross section, a helical conductor disposed in said annular space, the individual turns of said helical conductor being of greater diameter than the radial and axial dimensions of said annular space and tilted substantially diagonally of the cross section of said annular space by confinement therein, and said axially opposed faces maintaining the individual turns of said helical conductor in said diagonal tilt when said contact members are separated.

6. In a disconnect switch for use between bus sections comprising spaced axially aligned bus members, stationary contact members on said bus members, a tubular bridging member movable axially relative to said stationary contact members, manual means for moving said bridging member to connect and disconnect said bus members, a housing for enclosing said disconnect switch, said housing having a portion forming a bearing for slidably supporting said bridging member, a helically coiled conductor disposed annularly between one of said contact members and said bridging member and tilted obliquely thereacross, axially opposed faces on said bridging member for causing said conductor to move with said bridging member, a second helically coiled conductor disposed between the other contact member and said bridging member and tilted obliquely thereacross by contact with said other contact member and said bridging member, axially opposed faces on said other contact member between which said second conductor is disposed to prevent movement thereof, the individual turns of said second conductor being of greater diameter than the distance between the opposed faces on said other contact member and tilted sideways thereacross by contact with said axially opposed faces.

7. In a disconnect switch for use between bus sections comprising spaced axially aligned bus members, stationary contact members on said bus members, a tubular bridging member radially spaced from said contact members and axially movable relative to said contact members to connect and disconnect said bus members, a housing enclosing said disconnect switch and having a portion slidably supporting said bridging member, a helical conductor disposed annularly be tween one of said contact members and said bridging member and tilted obliquely thereacross, axially opposed faces on said bridging member for causing said helical conductorto move with said bridging member relative to said one contact member, said helical conductor being at all times in contact with said one contact member and said bridging member, axially opposed faces on the other of said contact members, said axially opposed faces and the radial space between said other contact member and said bridging member forming an annular space of substantially rectangular cross section, a second helical conductor disposed in said annular space, the individual turns of said second helical conductor being of greater diameter than the radial and axial dimensions of said annular space and tilted radially of said other contact member and substantially diagonally of the cross section of said annular space by confinement therein, and said axially opposed faces maintaining the individual turns of said second helical conductor in said diagonal tilt when said bridgin member is moved to disconnect said bus members.

STANLEY DAVID HOPPER. ERNST HEINRICH HERMANN HASSLER.

REFERENCES CITED The following references are of record in the die of this patent:

UNITED STATES PATENTS Number Name Date 1 968 869 Austin Aug. 7, 1934 2,229,006 Rudd Jan. 14, 1941 2,229,504 Hoye Jan. 21, 1941 FOREIGN PATENTS Number Country Date 7,057 Great Britain 1898 29,822 Great Britain 1913 186,526 Great Britain Oct. 5, 1922 186,527 Great Britain Oct. 5, 1922 685,738 Germany Dec. 23, 1939 

